1. Field of the Invention
The invention is based on a device for measuring a fill level of a liquid in a container.
2. Description of the Prior Art
A device for measuring a fill level is known from DE 199 42 378 A1, in which a ultrasonic transducer is disposed outside a fuel tank, near one end of a sound guide conduit that is provided between a container bottom and a top wall. The ultrasonic transducer sends ultrasonic waves into the sound guide conduit, and the ultrasonic waves are reflected at a surface of the fluid. The ultrasonic waves reflected are received by the ultrasonic transducer and evaluated in an evaluation unit. A fill level is ascertained from a transit time of the ultrasonic waves. A disadvantage of this is that a low level near the container bottom can no longer be measured, since when the level is low, the transit time of the emitted ultrasonic wave is so brief that the emitted ultrasonic wave has not yet decayed before the reflected ultrasonic wave already comes back. Thus the device has a comparatively high minimally measurable fill level.